I find that often while working with the study bar at the bottom, it will disappear and I will lose the ability to save, highlight,and to journal, create new notebooks etc. Sometimes this will go down for minutes at a time. Any idea why this happens?

When you change the width of the window to less than a certain number (I think it's 730?) of pixels, the study bar disappears because LDS.org thinks you're on a mobile device. Do you resize your browser window when you're studying?

Samuel Bradshaw • If you desire to serve God, you are called to the work.

I've observed this behavior at times, but it's been a while since I've seen it.

I believe what's happening is that your browser opens to the page with the content. After you get the content, your web browser tries to communicate with the "study service". If it can connect, then you get the study toolbar and highlighting. If it can't connect, then you don't get it.

I believe when I've seen the problem that the toolbar will disappear when I change pages, not necessarily disappear while I'm studying on a page. The frustrating thing is that I go to highlight and then I later find that the highlight didn't save. Usually when I run into the problem I try refreshing the page to see if I can get the study toolbar to appear when the page is refreshed.

There can be various reasons why the "study service" isn't available. Maybe the server is overloaded and doesn't respond in a timely manner, maybe it's temporarily down, maybe the load balancer directed you to a bad server, etc.